Toro 53854 Xtra Smart Wireless Weather Sensor Features: Saves money and helps comply with local water use restrictions Promotes healthy landscapes by preventing under or over watering Automatically adjusts your watering schedule to actual weather conditions Monitors temperature, rainfall, and solar radiation Use the "Quick Clip" bracket to attach easily to gutters or other locations Conservation device meets legislative standards in states/municipalities with mandates Uses industry standard hydroscopic discs to sense rain Designed exclusively to work with the EC-XTRA Indoor Timer Automatically shut-off stops watering when it rains or freezes Replaceable 9 volt battery (included) provides up to 5 year life Water Smart, Water Less